Adjustable curve.



K. W. NEVERS.

ADJUSTABLE CURVE.

APPLICATION mm APR.21. 1911.

1,258,357. Pat ented Mar. 5, 1918.

vvuemtoz KENNETH W. NEVERS, 0F A'IHOL, MASSACHUSETTS.

ADJUSTABLE CURVE.

Specification of Letters Patent.

Patented Mar. 5, 1918.

Application filed April 27, 1917. Serial No. 164,978.

i'or drawin muncrous curves which now require separate instruments, andwith this general object in view, the invention resides in the novelconstruction to be hereinafter fully described and claimed, thedescriptive matter being supplemented by the accompanying drawing whichforms a part of this specification and in which:

Figure 1 is a plan view;

Fig. 2 is an elevation of the front edge of the device;

Fig. 3 is a longitudinal section on the plane of the line 33 oi Fig. 1;and,

Fig. l is a detail horizontal section on the plane of the line %i-L oi.Fi 3.

In the drawings above briefly described the reference numerals 1designate a pair of divergent arms which are substantially rigidalthough yieldable to a slight extent, said arms being joined at theirinner ends by a connecting portion 2 which forms therewith a bow, saidportion having an opening through which. an adjusting bolt 3 passes.

A flexible resilient and preferably graduatecl rule t extends betweenthe ends of the arms 1 and is provided 011 its rear side with lugs 5received between ears 6 formed on said arms, pivot pins 7 being passedthrough said lugs and ears. The central portion of the rule 41 isreinforced by a leaf spring 8 having longitudinal slots 9 in its endsthrough which studs 10 extend from the rule. It is to the center of thespring 8 that the adjilsting bolt 3 is secured, said bolt having thereona nut 11 abutting a washer 12 hearing against. the connecting portion E2of the bow.

By constructing the device in the manner shown and described, adjustmentof the nut 11 will spring the rule la greater or less amount to adjustthe same for use in ruling straight lines or various curves. Theinvention is thus applicable for uses now requiring a great number ofseparate instrunients.

Since probably the best results are obtained from the specificconstruction shown, this construction. constitutes the preferred form ofthe device. I wish it understood, however, that within the scope of theinvention. as claimed, numerous minor changes may be made withoutsacrificing the principal advantages.

I claim:---

A drawing instrument of the class described comprising a how, a flexiblerule pivoted at its ends to the ends of said bow and having a pair ofinwardly extending studs, a flat reinforcing spring contacting with theinner side of said rule and having slots receiving said studs, and ascrewthreaded adjusting device extending between the center of said.spring and said how.

In testimony whereof I have hereunto set my hand in the presence of'twosubscribing witnesses.

KENNETH l V. NEVERS. Witnesses:

G. LESLIE Moonron, CHARLES l/V. FAULKNER.

Ooploo ol! this patent may he obtained for five cents each, byaddressing the Commissioner of latents,

Washington, D. G.

